Exploring the molecular interaction of mebendazole with bovine serum albumin using multi-spectroscopic approaches and molecular docking

Exploring the binding characteristics between lorlatinib and human alpha-1-acid glycoprotein: Multispectral and molecular modeling techniques

Approval in 2019 was granted for the highly selective, targeted agent lorlatinib, which primary target is ROS1 and ALK. The purpose of this work was to examine the binding mechanism between lorlatinib (LOR) and HAG employing multispectral and molecular modeling techniques. Fluorescence data demonstrated that LOR quenched HAG fluorescence as a static quenching, interecalated into the hydrophobic cavity of HAG with a moderate affinity. Thermodynamic and competitive experiments pointed out that LOR bound with HAG primarily through hydrogen bonding, hydrophobic, and van der Waals forces. Circular dichroism, three-dimensional and synchronous fluorescence spectroscopic studies noted that the secondary structure of HAG and microenvironments around tyrosine (Tyr) and tryptophan (Trp) residues were altered due to binding with LOR. The contribution of each energy involved in binding process of LOR and HAG has been analyzed by molecular simulation techniques. Besides, the environmental conditions with metal ions have also been studied. The present study is expected to provide a theoretical basis for further studying the metabolism of LOR in vivo, which may help to gain a deeper understanding of the general pharmacological activity of the drug.

Investigation of the molecular interaction between apraclonidine, an α2-adrenergic receptor agonist, and bovine serum albumin using fluorescence and molecular docking techniques

Apraclonidine (APR) is a potent and selective α2-adrenergic receptor agonist used in the diagnosis of Horner's Syndrome, and the residuals of APR that accumulate in tissues of animals can cause central nervous and cardiovascular systems influences in humans. Therefore, to understand the influence of APR on human health, we examined the interaction of APR with the carrier protein in plasma, bovine serum albumin (BSA). The BSA fluorescence signal was quenched due to the APU-BSA complex formation and a weak binding affinity was estimated between APR and BSA. The inclusion of fluorescence, UV-vis absorption, molecular docking, and dynamics simulation techniques employed to broadly investigate the combination of APR with BSA at typical physiological conditions. The thermodynamic results revealed that enthalpy (ΔH0) and entropy (ΔS0) changes were computed as +11.14 kJ mol-1 and +97.56 J mol-1 K-1, respectively, which represented the binding is principally entropy-driven and the hydrophobic forces acting a significant role in the reaction. Analysis of synchronous and 3-D fluorescence signals revealed microenvironmental variations close to BSA's Trp and Tyr residues upon APR addition. Both the competitive site marker as well as molecular docking results detected that APR exhibited a stronger binding affinity towards Drug Site 2 (DS2) compared to Drug Site 1 (DS1).

Pentagon-embedded N-doped coumarinacenes: tandem synthesis and tunable photophysical attributes for biomolecular probing

We have synthesized a novel series of nitrogen-doped pentagon-embedded coumarinacenes, namely carbazole-coumarins, via a tandem 1,4-elimination Diels-Alder aromatization reaction. These planar, N-substituted carbazole-coumarins exhibit excellent functionalizability, enhanced photostability and solvent polarity-tunable absorption and blue-to-red emission with notably high fluorescence quantum yields, attesting to their remarkable photophysical properties. These attributes highlight the carbazole-coumarins' potential as robust and efficient fluorescent materials for diverse applications in various fields, including as probes for studying biomolecular systems and dynamics.

Repositioning anthelmintics for the treatment of inflammatory-based pathological conditions

Acute, uncontrolled and/or long-lasting inflammation causes a breakdown in immunological tolerance, leading to chronicity and contributing to a series of significant local or systemic tissue changes. Anti-inflammatory efficacy, fewer adverse effects, improved selectivity, and curative action are imminent issues for patients suffering from chronic inflammation-related pathologies. Then, we performed a complete and critical review about anthelmintics, discussing the main classes and the available preclinical evidence on repurposing to treat inflammation-based conditions. Despite low bioavailability, many benzimidazoles (albendazole and mebendazole), salicylanilides (niclosamide), macrocyclic lactones (avermectins), pyrazinoisoquinolones (praziquantel), thiazolides (nitazoxanide), piperazine derivatives, and imidazothiazoles (levamisole) indicate that repositioning is a promising strategy. They may represent a lower cost and time-saving course to expand anti-inflammatory options. Although mechanisms of action are not fully elucidated and well-delineated, in general, anthelmintics disrupt mitogen-activated protein kinases, the synthesis of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-8, IL-12, and IFN-γ), the migration and infiltration of leukocytes, and decrease COX-2 expression, which impacts negatively on the release of prostanoids and leukotrienes. Moreover, some of them reduce nuclear accumulation of NF-κB (niclosamide, albendazole, and ivermectin), levels of nitric oxide (nitazoxanide and albendazole), and mucus, cytokines, and bronchoconstriction in experimental inflammatory pulmonary diseases (ivermectin and niclosamide). Considering the linking between cytokines, bradykinin, histamine, and nociceptors with algesia, anthelmintics also stand out for treating inflammatory pain disorders (ivermectin, niclosamide, nitazoxanide, mebendazole, levamisole), including for cancer-related pain status. There are obstacles, including the low bioavailability and the first-pass metabolism.

Unveiling the interaction, cytotoxicity and antibacterial potential of pyridine derivatives: an experimental and theoretical approach with bovine serum albumin

The binding interactions between bovine serum albumin (BSA) and three pyridine derivatives, i.e., 2-(5-bromopyridin-3-yl) acetic acid (L1), 3-bromo-5-nitropyridine (L2) and 2-chloro-4-nitropyridine (L3), have been carried out using UV-Vis and fluorescence spectroscopic methods. Fluorescence intensity quenching is observed by adding L2 and L3 to the BSA solution. The quenched fluorescence emission is due to the static nature. An isothermal titration calorimetry (ITC) experiment shows the binding ability of L1 with BSA. The binding constants are found to be 7.23 ± 0.32 × 105 M-1 for L1. The thermodynamic parameters were calculated from ITC measurements (i.e., ∆H = -2.78 ± 0.08 kcal/mol, ∆G = -5.65 ± 0.25 kcal/mol, and -T∆S = -2.87 ± 0.11 kcal/mol), which indicated that the protein-ligand complex formation between L1 and BSA is mainly due to the hydrogen bonds and van der Waals interactions. Cyclic voltammetry (CV) and structure activity and relationship (SAR) studies have been carried out to establish the relationship between ligands and proteins. Additionally, we conducted an antibacterial assay with gram-positive Staphylococcus aureus, Enterococcus faecalis, and negative bacterial strains Acinetobacter baumannii and Escherichia coli against L1, L2, and L3, aiming to address the challenges posed by the co-existence of multidrug-resistant bacteria. Finally, drosophila is used to test the cytotoxicity of ligands L1, L2, and L3's in vitro.

Metal complexes containing vitamin B6-based scaffold as potential DNA/BSA-binding agents inducing apoptosis in hepatocarcinoma (HepG2) cells

A ligand (HL) was synthesized from the pyridoxal hydrochloride (vitamin B6 form) and 1-(2-Aminoethyl)piperidine in one single step. The metal complexes [Zn(L)(Bpy)]NO3 (1), [Cu(L)(Bpy)]NO3 (2), and [Co(L)(Bpy)]NO3 (3) were prepared by tethering HL and 2,2'-bipyridine. The synthesized HL and metal complexes 1-3 were thoroughly characterized using spectroscopic techniques such as 1H NMR, 13C NMR, FTIR, EI-MS, molar conductance, and magnetic moment, in addition to CHN elemental analysis. The geometry of complexes was square pyramidal around the metal ions {Zn(II), Cu(II), and Co(II)}. The interaction of ligand and metal complexes with DNA and BSA macromolecules was accomplished by UV-Vis absorption and fluorescence spectroscopy in vitro. The hyperchromism in band at 303-325 with no shift supports the groove binding with some partial intercalation in grooves. Similarly, in BSA-binding studies, complex 2 shows greater binding potential in the hydrophobic core probably near the Trp-212 in the subdomain IIA. Furthermore, complex 2 shows excellent cytotoxicity on HepG2 cancer cells with IC50 = 25.0 ± 0.45 µM. The detailed analysis by cell-cycle studies shows cell arrest at the G2/M phase. The type of cell death was authenticated by an annexin V-FTIC dual staining experiment that reveals maximum death by apoptosis together with non-specific necrosis.

Spectroscopic investigation and structural simulation in human serum albumin with hydroxychloroquine/Silybum marianum and a possible potential COVID-19 drug candidate

In this study, the interaction between human serum albumin (HSA) and the hydroxychloroquine/Silybum marianum (HCQ/SM) mixture was investigated using various techniques. The observed high binding constant (Kb) and Stern-Volmer quenching constant (KSV) indicate a strong binding affinity between the HCQ/SM mixture and HSA. The circular dichroism (CD) analysis revealed that HCQ/SM induced conformational changes in the secondary structure of HSA, leading to a decrease in the α-helical content. UV-Vis analysis exhibited a slight redshift, indicating that the HCQ/SM mixture could adapt to the flexible structure of HSA. The experimental results demonstrated the significant conformational changes in HSA upon binding with HCQ/SM. Theoretical studies were carried out using molecular dynamics simulation via the Gromacs simulation package to explore insights into the drug interaction with HSA-binding sites. Furthermore, molecular docking studies demonstrated that HCQ/SM-HSA exhibited favorable docking scores with the receptor (5FUZ), suggesting a potential therapeutic relevance in combating COVID-19 with a value of -6.24 kcal mol-1. HCQ/SM exhibited stronger interaction with both SARS-CoV-2 virus main proteases compared to favipiravir. Ultimately, the experimental data and molecular docking analysis presented in this research offer valuable insights into the pharmaceutical and biological properties of HCQ/SM mixtures when interacting with serum albumin.

In vitro investigation of the binding characteristics of dacomitinib to human α 1-acid glycoprotein: Multispectral and computational modeling

Dacomitinib is a highly selective second-generation tyrosine kinase inhibitor that can irreversibly bind to tyrosine kinase and is mainly used in the treatment of lung cancer. The binding characteristics of dacomitinib with human α 1-acid glycoprotein (HAG) were analyzed by multispectral and computational simulation techniques. The fluorescence spectra showed that dacomitinib can quench the fluorescence of HAG by forming the HAG-dacomitinib complex with a molar ratio of 1:1 (static quenching). At the temperature similar to that of the human body, the affinity of dacomitinib to HAG (8.95 × 106 M-1) was much greater than that to BSA (3.39 × 104 M-1), indicating that dacomitinib will give priority to binding onto HAG. Thermodynamics parameters analysis and driving force competition experiments showed that hydrogen bonding and hydrophobic forces were the major sources for keeping the complex of HAG-dacomitinib stable. The experimental outcomes also showed that the binding of dacomitinib can lead to the loosening of the skeleton structure of HAG, which led to a slight change in the secondary structure, and also reduces the hydrophobicity of the microenvironment of Trp and Tyr residues. The binding sites of dacomitinib on HAG and the contribution of key amino acid residues to the binding reaction were determined by molecular docking and molecular dynamics (MD) simulation. In addition, it was found that there was a synergistic effect between dacomitinib and Mg2+ and Co2+ ions. Mg2+ and Co2+ could increase the Kb of dacomitinib to HAG and prolong the half-life of dacomitinib.

A hybrid nanoparticle-protein hydrogel system for prolonged local anesthesia

Local anesthetics are effective in relieving pain, but their duration of action is short. Therefore, the development of injectable sustained release systems to prolong the effect of local anesthetics has been of interest. In such systems delivering conventional local anesthetics, it has been challenging to achieve long durations of effect, particularly without incurring tissue toxicity. To overcome these challenges, we created a platform comprising a protein hydrogel incorporating hydrophobic local anesthetic (bupivacaine) nanoparticles. The nanoparticles were prepared by anti-solvent precipitation stabilized with bovine serum albumin (BSA), followed by crosslinking with glutaraldehyde (GA). The resulting BSA hydrogels prolonged release of bupivacaine in vitro. When bupivacaine nanoparticles within crosslinked BSA were injected at the sciatic nerve in rats, a duration of nerve block of 39.9 h was obtained, compared to 5.5 h for the commercial bupivacaine liposome suspension EXPAREL®. Tissue reaction was benign. We further demonstrated that this system could control the release of the amphiphilic drug diphenhydramine and the hydrophobic paclitaxel.

Molecular interactions and binding dynamics of Alpelisib with serum albumins: insights from multi-spectroscopic techniques and molecular docking

Alpelisib (ALP) is a potent anti-cancer drug showing promising activity against advanced breast cancers. Hence, profound understanding of its binding dynamics within the physiological system is vital. Herein, we have investigated interaction of ALP with human serum albumin (HSA) and bovine serum albumin (BSA) using spectroscopic techniques like absorption, fluorescence, time-resolved, synchronous and 3D-fluorescence, FRET, FT-IR, CD, and molecular docking studies. The intrinsic fluorescence of both BSA and HSA quenched significantly by ALP with an appreciable red shift in its emission maxima. Stern-Volmer analysis showed increase in Ksv with temperature indicating involvement of dynamic quenching process. This was further validated by no significant change in absorption spectrum of BSA and HSA (at 280 nm) upon ALP interaction, and by results of fluorescence time-resolved lifetime studies. ALP exhibited moderately strong binding affinity with BSA (of the order 106 M-1) and HSA (of the order 105 M-1), and the major forces accountable for stabilizing the interactions are hydrophobic forces. Competitive drug binding experiments and molecular docking suggested that ALP binds to site I in subdomain IIA of BSA and HSA. The Förster distance r was found to be less than 8 nm and 0.5 Ro < r < 1.5 Ro which suggests possible energy transfer between donors BSA/HSA and acceptor ALP. Synchronous and 3D-fluoresecnce, FT-IR and CD studies indicated that ALP induces conformational changes of BSA and HSA upon interaction.Communicated by Ramaswamy H. Sarma.

Interaction of food colorant indigo carmine with human and bovine serum albumins: A multispectroscopic, calorimetric, and theoretical investigation

In this work we have studied the interaction of the food dye Indigo-Carmine (IndC) with the most studied model transport proteins i.e. human and bovine serum albumin (HSA & BSA). A multispectroscopic approach was used to analyze the details of the binding process. The intrinsic fluorescence of both the albumins was significantly quenched by IndC and the quenching was both static and dynamic in nature with the former being dominant. The HSA-lndC and BSA-IndC distance after complexation was determined by Förster resonance energy transfer (FRET) method which suggested efficient energy transfer from the albumins to IndC. Thermodynamics of serum protein-IndC complexation was estimated by isothermal titration calorimetry (ITC) which revealed that the binding was enthalpy driven. Circular dichroism (CD) and FTIR spectroscopy revealed that the binding of IndC induced secondary structural changes in both the serum proteins. Synchronous and 3D fluorescence spectroscopy revealed that the binding interaction caused microenvironmental changes of protein fluorophores. Molecular docking analysis suggested that hydrogen bonding and hydrophobic interactions are the major forces involved in the complexation process.

Binding studies of potential amyloid-β inhibiting chalcone derivative with bovine serum albumin

Chalcones (α-phenyl-β-benzoylethylene) and their natural-source derivatives have been investigated for their remarkable biological activities, like neuroprotective, anti-inflammatory, and anti-tumor properties. A triazole chalcone ligand (E)-3-(4-(dimethylamino)phenyl)-1-(4-((1-(2-(4-((E)-3-(4(dimethylamino)phenyl)acryloyl)phenoxy)ethyl)-1H-1,2,3-triazol-4-yl)methoxy)phenyl)prop-2-en-1-one (L1) was synthesized by Cu(I)- catalysed click reaction. The mechanistic properties of L1 for therapy were evaluated by analyzing the binding interactions between L1 and bovine serum albumin (BSA) through photophysical and computational studies. The structural elucidation of ligand L1 was carried out by NMR and mass spectrometry. The Aβ inhibitory activity of L1 was studied by thioflavin T assay and transmission electron microscopy. The biomolecular interaction of L1 with bovine serum albumin was examined through multi-spectroscopic techniques in combination with in silico studies. UV-Visible absorption, fluorescence spectroscopy, circular dichroism, Förster resonance energy transfer, and three-dimensional fluorescence studies confirmed the formation of a BSA-L1 complex. The potential binding sites, mechanism of interactions, and variations in the environment of tyrosine and tryptophan amino acid residues of BSA were assessed at different temperatures. The binding constant for the Static quenching mechanism of intrinsic fluorescence of BSA was of the order of 105 M-1. The esterase enzyme activity assay in the presence of L1 revealed an increase in the protein enzyme activity. Molecular docking studies suggested L1 was predominantly bound to BSA by hydrogen bonds and Van der Waals forces.

Evaluating binding and interaction of selected pesticides with serum albumin proteins by Raman, 1H NMR, mass spectrometry and molecular dynamics simulation

Addressing the acute pesticide poisoning and toxicity to humans, is a global challenge of top priority. Serum albumin is the most abundant plasma protein, capable of binding with herbicide and pesticide residues. This study reports multifaceted approaches for in-depth and robust investigation of the molecular interactions of selected pesticides, including propanil (PPL), bromoxynil (BXL), metolachlor (MLR) and glyphosate (GPE) with bovine serum albumin (BSA) proteins using experimental (Raman and FTIR spectroscopy, native mass spectrometry and high field 1H NMR), molecular dynamics (MD) simulation and principal component analysis (PCA). The binding of pesticides with BSA resulted in BSA amide I and amide II Raman spectral shifts. PCA of Raman spectra of serum-pesticide complexes showed the grouping of pesticides on the score plot based on the similarities and differences in pesticides' chemical structures. Native mass spectrometry results revealed strong adduct formation of the pesticides with the protein. The observed changes in chemical shifts, peak broadening or peak disappearance of characteristic proton signals of the pesticides, indicated altered chemical environments due to binding BSA-pesticides interactions. The results of MD simulation conducted for over 500 ns revealed strong pesticides interaction with LEU197, LEU218, LEU237, TRP213, SER286 and ILE289 residues to the site I of BSA. Free energy landscapes provided insights into the conformational changes in BSA on the binding of pesticides. Overall, the experimental and computational results are in consonant and indicate the binding of pesticides into the site I and site II (sub-domain IIA) of the BSA via hydrogen bonding, non-covalent and hydrophobic interactions.Communicated by Ramaswamy H. Sarma.

Protein interactions, molecular docking, antimicrobial and antifungal studies of terpyridine ligands

Resistance to antibiotics/antibacterials/antifungals in pathogenic microbes has been developing over the past few decades and has recently become a commonplace public-health peril. Thus, alternative nontoxic potent antibiotic agents are covertly needed to control antibiotic-resistant outbreaks. In an effort to combat the challenges posed by the co-occurrence of multidrug resistance, two terpyridine ligands 4'-(4-N,N'-dimethylaminophenyl)-2,2':6',2″-terpyridine (L1) and 4'-(4-tolyl)-2,2':6',2″-terpyridine (L2) have been designed, prepared and confirmed their structure by spectral studies. Thereafter, antimicrobial assay was performed against gram positive and negative bacterial strains along with fungal strains. Both compounds L1 and L2 exhibited remarkable inhibitory activities against bacteria, Escherichia coli and Staphylococcus aureus at MIC values 6.25 and 3.125 µg/ml, respectively. In addition, in silico molecular docking studies were ascertained with bacterial DNA gyrase and fungal demethylase. Furthermore, both L1 and L2 could bind Bovine Serum Albumin (BSA) protein and binding interaction has been studied with the help of UV-Visible and fluorescence spectroscopy. While fluorescence of BSA unperturbed in the presence of L2, an addition of L1 to the solution of BSA resulted significant quenching. The binding constant calculations at different temperature confirmed that the fluorescence quenching between BSA and L1 is predominantly static in nature. The toxicity of L1 and L2 was checked using Drosophila melanogaster. The toxicity analysis suggest both the dyes are non-cytotoxic in nature.Communicated by Ramaswamy H. Sarma.

Investigating sulfonamides - Human serum albumin interactions: A comprehensive approach using multi-spectroscopy, DFT calculations, and molecular docking

The environmental and health risks associated with sulfonamide antibiotics (SAs) are receiving increasing attention. Through multi-spectroscopy, density functional theory (DFT), and molecular docking, this study investigated the interaction features and mechanisms between six representative SAs and human serum albumin (HSA). Multi-spectroscopy analysis showed that the six SAs had significant binding capabilities with HSA. The order of binding constants at 298 K was as follows: sulfadoxine (SDX): 7.18 × 105 L mol-1 > sulfamethizole (SMT): 6.28 × 105 L mol-1 > sulfamerazine (SMR): 2.70 × 104 L mol-1 > sulfamonomethoxine (SMM): 2.54 × 104 L mol-1 > sulfamethazine (SMZ): 3.06 × 104 L mol-1 > sulfadimethoxine (SDM): 2.50 × 104 L mol-1. During the molecular docking process of the six SAs with HSA, the binding affinity range is from -7.4 kcal mol-1 to -8.6 kcal mol-1. Notably, the docking result of HSA-SDX reached the maximum of -8.6 kcal mol-1, indicating that SDX may possess the highest binding capacity to HSA. HSA-SDX binding, identified as a static quenching and exothermic process, is primarily driven by hydrogen bonds (H bonds) or van der Waals (vdW) interactions. The quenching processes of SMR/SMZ/SMM/SDX/SMT to HSA are a combination of dynamic and static quenching, indicating an endothermic reaction. Hydrophobic interactions are primarily accountable for SMR/SMZ/SMM/SDX/SMT and HSA binding. Competition binding results revealed that the primary HSA-SAs binding sites are in the subdomain IB of the HAS structure, consistent with the results of molecule docking. The correlation analysis based on DFT calculations revealed an inherent relationship between the structural chemical features of SAs and the binding performance of HSA-SAs. The dual descriptor (DD) and the electrophilic Fukui function were found to have a significant relationship (0.71 and -0.71, respectively) with the binding constants of HSA-SAs, predicting the binding performance of SAs and HSA. These insights have substantial scientific value for evaluating the environmental risks of SAs as well as understanding their impact on biological life activities.

Comparative molecular docking and toxicity between carbon-capped metal oxide nanoparticles and standard drugs in cancer and bacterial infections

Introduction

Nanoparticles (NPs) are of great interest in the design of various drugs due to their high surface-to-volume ratio, which result from their unique physicochemical properties. Because of the importance of examining the interactions between newly designed particles with different targets in the case of various diseases, techniques for examining the interactions between these particles with different targets, many of which are proteins, are now very common.

Methods

In this study, the interactions between metal oxide nanoparticles (MONPs) covered with a carbon layer (Ag2O3, CdO, CuO, Fe2O3, FeO, MgO, MnO, and ZnO NPs) and standard drugs related to the targets of Cancer and bacterial infections were investigated using the molecular docking technique with AutoDock 4.2.6 software tool. Finally, the PRO TOX-II online tool was used to compare the toxicity (LD50) and molecular weight of these MONPs to standard drugs.

Results

According to the data obtained from the semi flexible molecular docking process, MgO and Fe2O3 NPs performed better than standard drugs in several cases. MONPs typically have a lower 50% lethal dose (LD50) and a higher molecular weight than standard drugs. MONPs have shown a minor difference in binding energy for different targets in three diseases, which probably can be attributed to the specific physicochemical and pharmacophoric properties of MONPs.

Conclusion

The toxicity of MONPs is one of the major challenges in the development of drugs based on them. According to the results of these molecular docking studies, MgO and Fe2O3 NPs had the highest efficiency among the investigated MONPs.

Synthesis, Biological, Spectroscopic and Computational Investigations of Novel N-Acylhydrazone Derivatives of Pyrrolo[3,4-d]pyridazinone as Dual COX/LOX Inhibitors

Secure and efficient treatment of diverse pain and inflammatory disorders is continually challenging. Although NSAIDs and other painkillers are well-known and commonly available, they are sometimes insufficient and can cause dangerous adverse effects. As yet reported, derivatives of pyrrolo[3,4-d]pyridazinone are potent COX-2 inhibitors with a COX-2/COX-1 selectivity index better than meloxicam. Considering that N-acylhydrazone (NAH) moiety is a privileged structure occurring in many promising drug candidates, we decided to introduce this pharmacophore into new series of pyrrolo[3,4-d]pyridazinone derivatives. The current paper presents the synthesis and in vitro, spectroscopic, and in silico studies evaluating the biological and physicochemical properties of NAH derivatives of pyrrolo[3,4-d]pyridazinone. Novel compounds 5a-c-7a-c were received with high purity and good yields and did not show cytotoxicity in the MTT assay. Their COX-1, COX-2, and 15-LOX inhibitory activities were estimated using enzymatic tests and molecular docking studies. The title N-acylhydrazones appeared to be promising dual COX/LOX inhibitors. Moreover, spectroscopic and computational methods revealed that new compounds form stable complexes with the most abundant plasma proteins-AAG and HSA, but do not destabilize their secondary structure. Additionally, predicted pharmacokinetic and drug-likeness properties of investigated molecules suggest their potentially good membrane permeability and satisfactory bioavailability.

Molecular interaction of lysozyme with therapeutic drug azithromycin: Effect of sodium dodecyl sulfate on binding profile

This paper describes an inclusive biophysical study elucidating the interaction of therapeutic drug azithromycin (Azith) with hen egg white lysozyme (HEWL). Spectroscopic and computational tools have been employed to study the interaction of Azith with HEWL at pH 7.4. The fluorescence quenching constant values (Ksv) exhibited a decrease with the increase in temperature which revealed the occurrence of static quenching mechanism between Azith and HEWL. The thermodynamic data demonstrated that hydrophobic interactions were predominantly involved in the Azith-HEWL interaction. The negative value of standard Gibbs free energy (ΔG°) stated that the Azith-HEWL complex formed via spontaneous molecular interactions. The effect of sodium dodecyl sulfate (SDS) surfactant monomers on the binding propensity of Azith with HEWL was insignificant at lower concentrations however the binding significantly decreased at increased concentrations of the former. Far-UV CD data revealed alteration in the secondary structure of HEWL in the presence of Azith and the overall HEWL conformation changed. Molecular docking results revealed that the binding of Azith with HEWL takes place through hydrophobic interactions and hydrogen bonds.